This disclosure relates to semiconductor fabrication, and, in particular, to film dispensing/coating and developing processes and systems.
Various microfabrication processes using coater/developer tools specify different chemicals to be dispensed onto a substrate (wafer) for particular designs. For example, various resist (photoresist) coatings can be dispensed onto a substrate surface. Resist coatings can vary by type of reaction to actinic radiation (positive/negative) and also by composition for different stages of patterning (front-end-of line, metallization, et cetera). Additionally, various developers and solvents may be selected to be dispensed onto a wafer. One challenge, however, in being able to dispense various chemicals onto a wafer is avoiding defects in the dispensed chemicals. Any small impurity or coagulation in the chemical can create defects on a wafer. As semiconductor features continue to decrease in size, avoiding and preventing defects from dispensed chemicals becomes increasingly important.